Green Envy

GREEN ENVY

Can a refined super-bike still be the best superbike?

DON CANET

SINCE ITS INTRODUCTION TWO YEARS AGO, Kawasaki’s ZX-10R has squashed the competition. The green monster roared to repeat wins in the annual Master Bike competition held each spring in Spain, a track-focused comparison test that includes every current sportbike of significance and attracts some serious racing talent to twist the throttles. The 10R has also edged out the competition in Cycle World s past two street/track liter-class shootouts and has been named Best Superbike in CWs Ten Best Bikes voting two years running. Its strength in many areas has enabled it to achieve these feats in spite of its few niggling flaws. Kawasaki has been paying attention. Rather than trumpeting the accolades and ignoring the niggles, it has thoroughly updated the ZX-10R, addressing the criticisms made by this and other publications, while seeking to give the bike a more controllable nature that would translate into quicker lap times. A strengthened crankcase and tighter tolerances in the shift mechanism have eliminated the occasional missed shifts that plagued the old bike, while adjustments to chassis geometry and the addition of a steering damper (yeah!) offer an improvement in overall stability. A new instrument cluster featuring an analog tachometer offers

another answer to our cries regarding the difficultto-read LCD rev-counter that first appeared on the ZX-636. Unfortunately, its tinted lens-offering UV protection for the digital LCD speedometer-still makes it hard to read the new tachometer under certain lighting conditions. Still, an improvement.

I traveled to Japan for a ride on the new Ninja at its birthplace, a rare opportunity, as Kawasaki Heavy Industries traditionally hands the responsibility of conducting new-model press launches to its overseas importers. The visit included a tour of the Kawasaki plant to see various models, including the 10R, rolling off the assembly line, and where we were introduced to the ZX-10R design team, all fairly young. That evening, our group of 20 international journalists dined with the head honchos of KHI’s consumer products division, enjoying a spectacular view overlooking Kobe from the top floor of the corporate high-rise. While all this was well and good-particularly the flame-grilled beef-a sack lunch would have sufficed. The biggest attractions were the bike and Kawasaki’s new test track where we rode it.

CW FIRST RIDE

KAWASAKI ZX-10R

Two days were spent riding the 10R at the Autopolis circuit located in the mountains of Kyushu in southern Japan. The facility was constructed in 1990 with no expense spared in preparation to host a round of the Formula One World Championship. Unfortunately, the Japanese economy took a big hit before an event was ever held, and due to its operational costs, the fabulous circuit has seen little use over the years. Kawasaki purchased Autopolis this past spring and used the 20-turn, 2.9-mile track extensively in the final development of the latest ZX-10R.

After putting in 50-plus laps aboard the Kawi around its nesting ground, I have to say the mean, green machine did feel more manageable.. .at least on this particular circuit. Aside from its fairly smooth surface, sitting 3000 feet above sea level puts Autopolis high enough in elevation to take some bite out of any engine’s power output. Check the NHRA’s correction-factor table if you need evidence of this. Mother Nature’s dulling of the lOR’s teeth could, in part, account for the bike feeling less wheelie-prone on the gas than its predecessor. Compared to the white-knuckled experience I had while turning hot laps at the bayside Infineon Raceway during our June, 2004, shootout, the bike I rode at Autopolis felt relatively tame.

In any case, the addition of an Öhlins steering damper as standard equipment on the ’06 model now offers a sense of security that the old bike lacked. Aboard the new 10,1 never felt like I was riding the razor’s edge or flirting with the possibility of the bike busting into a violent headshake. A nod to Kawasaki for choosing a fully adjustable, race-quality damper, too.

There have also been a number of chassis changes aimed at improving the bike’s roll response and rear tire grip. The engine now sits slightly higher in the frame, moving crank mass closer to the bike’s eg. Raising the engine has also allowed the generator to be relocated from behind the cylinders to the left end of

the crankshaft without sacrificing any cornering clearance. This move has eliminated the friction-related power loss of

the previous gear-driven system. The steering head has been moved forward 10mm and the rake kicked out to 24.5 degrees, shifting chassis weight bias rearward. These changes, along with the higher eg, are said to have lightened steering in spite of a 10-pound weight gain based on claimed figures. The swingarm is new, as well, and while slightly shorter from pivot to axle, it now offers the clearance required for larger-diameter race tires. A short 54.2-inch wheelbase is maintained. The swingarm pivot has been lowered 10mm to tune the

drivechain’s torque effect on the rear suspension for improved traction. On the stock Dunlop radiais with standard suspension settings during the first two sessions, handling proved light and neutral, although grip was fairly limited. The sus-

pension felt more compliant than on last year’s model, particularly at the rear. After two journalists experienced front-end-related crashes, race-compound Qualifier GP tires were spooned on and suspension settings firmed up for the remaining four sessions. The increased traction painted a clearer picture of the bike’s on-track capabilities.

Hustling down the 2900-foot-long front straight with my chin pressed into the fuel tank’s recessed top, I was comfortably tucked out of the 160-mph windblast. Pinpointing my shut-off point through the lightly tinted screen’s clear optics as the engine accelerated through fifth gear, I noted a reduction of mechanical noise emitted by the revised powerplant. Popping up and bracing myself at the brake marker, a firm two-finger squeeze on the lever of the new Nissin radialpump master cylinder-first used on the ZX-636-provided plenty of stopping force. While the radial-mount Tokico four-piston, four-pad calipers and 300mm petal rotors are unchanged, I experienced no inconsistency in the amount of lever travel-a known issue with the previous-generation

I OR. I now had complete confidence to move the six-position lever closer to the bar where I prefer it.

This year’s engine features a heavier crankshaft, which along with the same back-torque-limiting slipper clutch, makes corner entries very controllable. It’s easy to maintain steady lever pressure during braking, as there’s no need to blip the throttle to match revs during downshifting. Charging into Autopolis’ second-gear Turn 1 or steep, downhill Turn

II demonstrated how effective the setup functions, as I never once experienced any rear-wheel hop. The additional crank inertia pays dividends throughout the corner as well, helping smooth the transition back onto the throttle and giving greater control when dialing on the power at the exit.

In part, the improved response and control is owed to the dual-throttle-valve fuel-injection system’s use of a new ultrafine injector that has improved atomization. Actually, the entire intake tract has been revamped from ram-air inlet to air-box to throttle body to intake port to a 1mm reduction in intake-valve diameter; all for optimizing charge velocity and cylinder fill.

Kawasaki engineers have met stricter Euro-III emissions standards without relinquishing any of the lOR’s awesome performance. Along the way, power delivery has been smoothed throughout the rev range, again making it possible to get on the gas sooner in the comer. This was the case at every turn of the track, even a first-gear hairpin where it was particularly evident that this bike has less drivetrain lash than its predecessor. Controlling traction at the rear, especially as the tires wore, was notably easier than what I recall aboard last year’s bike. While overall stability felt markedly improved, the front still gets quite light when on the throttle hard out of corners-then again, most of Autopolis’ turns were taken in second gear! As previously stated, though, wheelies were not much of an issue, the front wheel only truly lofting when given a tug of encouragement on the bars or a sharp snap to right the bike out of a corner. I’m anxious to see what happens when riding the 10R back home by the sea.

Another nice addition is the textured seat skin, which held me securely in place, allowing a relaxed hold on the clip-ons when accelerating off corners. My seat-of-the-pants assessment, then, indicates that once we’ve ridden the new Ninja on public roads and familiar racetracks, we’ll find it a much better bike than its predecessor. Raw performance has ruled for two years running; now we’ll see if refinement can be had without losing the bike’s edge. I’m guessing that won’t be an issue.